The use of completely digitized communication systems such as the Integrated Service Digital Network (ISDN) is becoming more common. Such systems offer voice, data, and graphical transmissions to the consumer. By replacing analog voice systems with digital capability, tremendous amounts of information of high quality can be transmitted along copper wires which are used as digital channels.
To carry a digital signal on an analog line, a modem must be used to generate signals of different frequency to represent digital bits. By comparison, a completely digital system does not require a modem. Network interface devices are used to access the system. The standard data rate for an ISDN system is 64 kilobits per second (Kbps). Terminal equipment such as a D4 bank or digital private exchange (PBX) can be used to interface a plurality of terminal equipment with a central exchange device. For example, the D4 bank can service 24 remote subscribers, each having a transmit line and a receive line which can operate at up to 64 Kbps. As noted above, digitized voice, data, video, and graphics can be transmitted from each remote subscriber. Moreover, bulk data transfers can be accomplished by using all 24 remote channels simultaneously.
Digital communication systems supply large amounts of data, voice, and video information at a high signal to noise ratio with a minimum of distortion and efficient interface transfer capability. To assure that such a digital system operates at its optimum characteristic, each communication channel in the system must be fully operational and in the proper state. Presently, manual adjustment the individual channel units for each channel is required to enable the channel to perform such functions as automated provisioning, performance reporting, status reporting, alarm reporting. These manual methods are typically awkward, inefficient and labor intensive.